条形荷载作用下梯度饱和土的动力响应分析

根据Biot波动理论，研究了条形均布荷载作用下非均匀饱和土地基的动力响应问题。利用Fourier积分变换，通过Helmholtz矢量分解原理，建立了饱和土层在动荷载作用下的回传射线矩阵法计算列式，考虑饱和土的物理力学性质沿深度方向按幂函数连续变化，采用数值Fourier逆变换获得了饱和土地基的位移、应力和孔隙压力等物理量的数值解。分析讨论了材料非均匀性对饱和土介质动力特性的影响。结果表明，非均匀饱和土的动力行为与均匀饱和土有着明显的不同，当土体的非均匀程度越高，条形荷载中点下流体压力和应力幅值越大，而位移、流体压力以及应力等物理量在水平方向的振动频率均随着土体非均匀变化程度的增强而增大。

Dynamic response analysis of graded fluid-saturated soil under strip load

Based on the Biot’s theory of porous media, the dynamic response of heterogeneous saturated soil subjected to strip loading is researched. Applying the Helmholtz vector decomposition and Fourier transformation, the calculation formula of reverberation ray matrix method (RRMM) is established for two-dimensional transient response of fluid-saturated soil. Assuming that the material properties of the saturated soil have an exponential law distribution along the thickness-coordinate, by using numerical inverse Fourier transformation, the displacement, the stress and the pore pressure are obtained. The effect of heterogeneity on transient responses of graded saturated soil is demonstrated and discussed. The numerical result shows that there is a significant difference on dynamic response between heterogeneous saturated soil and homogeneous saturated soil. The amplitude of fluid pressure and stresses that right below the middle point of the strip load is increased when the soil heterogeneous degree becomes high. In addition, the vibration frequencies of displacement, fluid pressure and stress increase with the increasing of soil heterogeneous degree along the horizontal direction.